CHICAGO -- May 16, 2017 -- The use of an insertable cardiac monitor (ICM) was effective in detecting “silent” atrial fibrillation (AF) in patients at high risk for AF and stroke, according to a study presented here at the 38th Annual Scientific Sessions of the Heart Rhythm Society (HRS).
“Atrial fibrillation unknown by patients or physicians is not uncommon,” said James A. Reiffel, MD, Division of Cardiology, Columbia University, and New York Presbyterian Hospital, New York, New York. “Patients can have AF without having symptoms, so they do not present themselves [to physicians]. There are a significant number of strokes that present without a prior history of AF. Lo and behold, you evaluate patients and find out that they have AF.”
The prospective, single-arm, multicentre study evaluated the presence and quantified the incidence of AF lasting at least 6 minutes in patients with unrecognised AF but at high risk for AF, such as patients with heart failure, hypertension, diabetes, and vascular disease.
The main outcome from the study was detection of AF at 18 months with secondary outcomes being detection rates from 30 days to 30 months. The researchers also looked at detection rates stratified by patients CHADS2 scores.
A total of 385 patients received an ICM and were followed for 22.5 months. The AF detection rate at 18 months was 29.3% with the rate as high as 40.0% at 30 months.
“The yield of the device is impressive,” said Dr. Reiffel, noting that 30 days of monitoring is often not sufficient to detect AF.
The AF detection rate did not differ by CHADS2 scores (P = .23). The median time from the time of insertion of the ICM to identification of the first AF episode was 123 days.
The technology was extremely well-tolerated, and its use did not produce any adverse events, said Dr. Reiffel.
More than half of the patients were prescribed oral anticoagulants after the identification of AF to reduce the risk of stroke.
Funding for this study was provided by Medtronic, Inc.
[Presentation title: High Incidence of Previously Unknown (Silent) Atrial Fibrillation in Patients at High Risk for Atrial Fibrillation and Stroke: Primary Results From the REVEAL-AF study. Abstract C-LBCT02-05]